首先简介一般加时间Ｐｅｔｒｉ网模型及其使能规则和点火规则，然后给出几种典型的加时间的Ｐｅｔｒｉ网模型及其动态行为及点火规则，其中，通讯时间Ｐｅｔｒｉ网侧重于网与环境之间的通讯；ＴＣＰＮ 侧重于讨论变迁的最早和最晚点火时间以及点火持续时间；ＧＳＰＮ 侧重于从概率的角度讨论变迁的点火时间问题，本文还给出三种具有代表性的用于描述多媒体同步的Ｐｅｔｒｉ网模型及其点火规则． First of all, we introduce the general plus time Petri nets model, its enabling rules and ignition rules. Then, we present some typical additive Petri nets models and their dynamic behaviors and ignition rules. Among them, the communication time Petri nets focus on the network and the environment TCPN focuses on discussing the earliest and latest ignition time and ignition duration of the transition; GSPN focuses on discussing the ignition timing of transition from the perspective of probability. In this paper, we also give three representative models for describing multimedia synchronization Petri net model and its ignition rules.